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Brown, C. J.

Publications and source records attributed to Brown, C. J..

At least 19 recordsLinked to original sources

The Everything Bagel Feature Finder: Ultra-fast automated feature finding for untargeted metabolomics

Metabolomics studies are increasingly being applied with hundreds to thousands, even tens of thousands of samples that demand rapid, automated data processing while maintaining analytical sensitivity or quantitative accuracy. A major computational bottleneck is feature finding, which is the transformation of LC-MS and LC-MS/MS data into a set of analyte signals aligned and quantified across samples. Feature finding can be computationally intensive and often requires manual iterative parameter optimization. To accelerate this process, we present the Everything Bagel (EB) feature finder, an ultra-fast automated feature finding tool that integrates feature detection, retention-time alignment, and gap filling designed for run-time and memory efficiency. We benchmarked EB against two automated feature finding methods on eight benchmarking datasets. Specifically, we evaluated these three feature finding methods by measuring spike-in standard detection coverage, dilution series quantification accuracy, and yeast 12C/13C credentialed features. In this evaluation, the EB feature finder achieved performance comparable to, and often exceeding, existing methods while requiring up to 150-fold lower CPU hours and up to 113-fold lower wall time. We further demonstrated the bioanalytical validity of EB by reanalyzing published datasets used for biomarker discovery and reproduced biologically significant features that matched the published findings using manually tuned feature finding settings. Taken along with the speed improvements, we anticipate EB will enhance the ability to automatically analyze datasets with thousands to tens of thousands of samples for the community.

bioinformatics↗

Detecting DNA methylation patterns suggestive of variable escape from X-chromosome inactivation

The X chromosome is often excluded from studies analyzing associations between traits and DNA methylation. In females, one copy of most genes on the X is inactivated (X-chromosome inactivation; XCI) through DNA methylation of the gene promoter on the inactive X. This leads to challenges in analyzing and interpreting DNA methylation data patterns. Particularly for sex-biased diseases and traits, there may be many loci of interest on the X chromosome, which contains about 5% of the genome. To address the need for appropriate analysis of DNA methylation data on the X chromosome, we develop a statistical approach to infer locus-specific escape from XCI sensitive to phenotype or covariate values. Performance of this method is illustrated by analysis of data from two sex-biased traits: rheumatoid arthritis which is 3-fold more common in females, and recurrent venous thromboembolism which occurs 2.5 times more often in males. Analyses of these two datasets identify new trait-associated loci on the X chromosome, demonstrate the capabilities of the new method for both bisulfite sequencing data and Illumina EPIC data, suggest at least one locus where variable escape may explain a sex-specific disease association, and rule out variable escape as a potential explanation at other loci. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=176 HEIGHT=200 SRC="FIGDIR/small/732395v1_ufig1.gif" ALT="Figure 1"> View larger version (52K): org.highwire.dtl.DTLVardef@108c23aorg.highwire.dtl.DTLVardef@77dc0org.highwire.dtl.DTLVardef@1d105d0org.highwire.dtl.DTLVardef@1d4b543_HPS_FORMAT_FIGEXP M_FIG C_FIG Created with BioRender (bioRender.com)

genomics↗

Developmental scarcity induces sex differences in social recognition and CA2 perineuronal nets

Early-life adversity has a lasting negative impact on social behavior in both humans and rodents. Sex differences exist in functional outcomes of postnatal stress, but underlying mechanisms remain incompletely explored. Using the limited bedding and nesting paradigm, a mouse model of developmental scarcity, we found sex differences in social behavior with adult males showing impaired social recognition and adult females showing intact social recognition with enhanced social novelty preference. Perineuronal nets, specialized extracellular matrix structures, are known to inhibit developmental plasticity and are concentrated in the CA2 region of the hippocampus in adulthood. We found higher intensity of CA2 perineuronal nets in adult males, but not adult females, after early life adversity. Focal degradation of the extracellular matrix in the CA2 region restored social recognition function in adult males previously subjected to early stress, suggesting that the effects of developmental adversity may be overcome by targeted intervention in adulthood.

neuroscience↗

Optimizing seagrass planting arrangements for animal benefits in a multi-habitat restoration seascape

Restoring lost and degraded ecosystems to enhance biodiversity and ecosystem services is a global priority, and animal responses to the restoration of habitats are a critical but undervalued component. Identifying the key drivers of animal colonization in restored habitats provides critical insights for restoration practitioners seeking to maximize ecological outcomes. When integrated into predictive frameworks and spatial decision- support tools, this knowledge becomes especially valuable for strategic planning, particularly in complex multi-habitat restoration projects where spatial configuration remains a crucial yet understudied dimension influencing ecosystem recovery trajectories. We collect and analyze animal data from one of the worlds largest multi- habitat coastal restoration systems in Denmark, comprising restored seagrass (Zostera marina), boulder reefs and mussel reefs. Using fine-scale spatial patterns in population abundances, we develop spatially explicit predictions across the seascape for various seagrass restoration scenarios and produce a series of optimizations, showing that it is practical to configure restoration to optimize biodiversity objectives, including those linked with fished species. Species-specific responses translated to variable outcomes across restoration scenarios and optimizations. While the optimal number and arrangement of restored patches varied depending on the target species or species group (e.g., fisheries species or seagrass specialists), one near-ubiquitous arrangement was patchy seagrass planting. This aligns with current practice, maximizes restoration efficiency, and highlights the importance of not homogenizing seascapes for biodiversity. Our approach provides a practical framework for incorporating animal monitoring data into restoration planning, helping practitioners design and optimize spatial planting configurations to achieve specific ecological objectives. Open Research StatementAll data and code/scripts (R language), including a README file, are freely available at: https://github.com/msievers100/DenmarkSpatial

ecology↗

Assessing predictive accuracy of species abundance models in dynamic systems

Cascading human pressures and environmental change are affecting the natural dynamics of animal populations. Forecasting population abundances from time-series data provides an important avenue for testing competing ecological theories, and for supporting conservation planning and sustainable use, yet changing system dynamics may lead to erroneous predictions. Predictions from a model fitted and tested on historical system dynamics may become irrelevant if system dynamics change. Here we describe methods to test forecast skill in a rapidly changing system where model parameters are likely to be non-stationary. We presented two ways to split time-series into training and test datasets so that training data were: 1) contemporary to the testing data ( modern split), and 2) not contemporary to the testing data ( legacy split). As a case-study, we use animal abundance data from a 30-year time-series from a global warming hotspot. We tested our approach on four temperate reef species with different temporal trends. The case-study and simulation tests confirmed larger forecast errors in legacy split when compared to the modern split. We found that the legacy split had errors that could be more than for times larger for a species that had a rapid collapse in abundance and non-stationary population dynamics. As expected for the species with rapid collapse, the legacy split estimated much higher forecast error than the modern split. Our approach is applicable to a large range of species and systems, including fisheries and threatened species population monitoring, where rapidly changing environments present threats to both the species and management efficacy. Accumulated lessons from across species and systems should shed light on critical generalities that precede broader ecosystem change.

ecology↗

Predicting the impact of giant kelp restoration on food webs and fisheries production

1. Ecosystem restoration is gaining momentum as communities and policymakers increasingly appreciate the need to recover lost ecosystem services. However, more knowledge about the potential ecological outcomes of restoration for ecosystem services is needed to promote engagement of stakeholders with restoration targets. In Tasmania the giant kelp, Macrocystis pyrifera, is a productive canopy species that has declined by 95%. 2. We aimed to predict the effects of M. pyrifera restoration on foodwebs and fisheries production. The primary productivity multiple of M. pyrifera compared to the dominant understory species Ecklonia radiata was quantified and then incorporated into an Ecopath with Ecosim (EwE) model of Tasmanian waters. The model was fitted to catch per unit effort data to estimate the predator/prey interactions. Several scenarios were then simulated, representing uncertainty in predator/prey interactions and different areas of M. pyrifera restoration. 3. Restoration of degraded reefs with M. pyrifera was predicted to increase primary productivity by about 40 times per unit area compared to the existing habitat. 4. We predicted that restoring 30% of the degraded M. pyrifera area would increase abalone and coastal demersal fish catch rates by [~]7%. Rock lobster and reef-associated fisheries catch rates were predicted to increase by 1-2% respectively. 5. Model scale was hypothesized to underestimate the increases in biomass and catch. By modelling outcomes of ecological restoration, achievable targets can be set that are locally relevant and therefore more likely to attract support.

ecology↗

Spread of a single superclone drives insecticide resistance in Acyrthosiphon kondoi across an invasive range

Populations under similar selection pressures may adapt via parallel evolution or dispersal of advantageous alleles. Here, we investigated insecticide resistance in the invasive blue-green aphid, Acyrthosiphon kondoi, which reproduces clonally in Australia and has rapidly developed resistance across geographic locations. Using genomic, transcriptomic, and experimental approaches, we explored the evolutionary origins and molecular mechanisms of resistance. We developed the first nuclear genome assembly for A. kondoi (443.8 Mb, 28,405 annotated genes, BUSCO score 97.5%) and a partial mitochondrial assembly (11,598 bp). All resistant strains shared a common ancestor, supporting the spread of a resistant superclone lineage that is distinct from susceptible strains. Resistance was associated with over-expression of an esterase gene that was homologous to E4/FE4 esterases in other aphid pests that are linked to resistance. Functional experiments in Drosophila melanogaster confirmed a causal role of this E4- like esterase in resistance to organophosphates, carbamates, and pyrethroids. These findings highlight how clonal dispersal and insecticide overuse can transform local adaptation into a widespread pest management issue. Our results suggest a parallel macroevolutionary response to insecticide selection in A. kondoi and other aphid species at the gene family level, but with a distinct regulatory mechanism in A. kondoi. Given the rapid spread of the resistant superclone, alternative management strategies, including expanded chemical control options and enhanced biological control, are urgently needed to mitigate this growing pest problem.

evolutionary biology↗

Retrieval of developmental social memories requires activation of the adult-born granule cell-CA2 circuit in mice

Adult-born granule cells (abGCs) project to the CA2 region of the hippocampus, but it remains unknown how this circuit affects behavioral function. Here we show that abGC input to the CA2 of adult mice is involved in the retrieval of remote developmental memories of the mother. Ablation of abGCs impaired the ability to discriminate between a caregiving mother and a novel mother, and this ability returned after new neurons were regenerated. Chemogenetic inhibition of projections from abGCs to the CA2 also temporarily prevented the retrieval of remote mother memories. These findings were observed when abGCs were inhibited at 4-6 weeks old, but not when they were inhibited at 10-12 weeks old. We also found that abGCs are necessary for differentiating features of CA2 network activity, including theta-gamma coupling and sharp wave-ripples, in response to novel versus familiar social stimuli. Taken together, these findings suggest that abGCs are necessary for neuronal oscillations associated with discriminating between social stimuli, thus enabling retrieval of remote developmental memories of the mother by their adult offspring.

neuroscience↗

Design-Rules for Stapled Alpha-Helical Peptides with On-Target In Vivo Activity: Application toMdm2/X dual antagonists

Stapled -helical peptides can bind to and modulate historically intractable targets while addressing the traditional liabilities associated with peptide therapeutics. However, their pipeline advancement has been impeded by the challenges of identifying peptides with sufficient cellular uptake to engage the target protein while lacking off-target toxicities. Here, we advance the field to arrive at a workflow for identifying advanced stapled peptide lead molecules with on-target in vivo activity with no off-target cell proliferation effects. Specifically, we generated a >350-member library based on ATSP-7041, a stapled peptide Mdm2(X) antagonist with validated on-target cellular effects but with significant off-target activity. Key insights from library analysis include 1) a clear correlation between lipophilicity and permeability, 2) removal of positive charge to avoid off-target toxicities, 3) judicious placement of anionic residues to enhance peptide solubility/behavior, 4) optimization of C-terminal length and helicity to enhance cell activity, 5) optimization of staple type/number to avoid polypharmacology. Incorporation of one or more of these attributes led to molecules with improved in vitro and in vivo activities (up to a >292x improved cell proliferation EC50). A subset of peptides were devoid of off-target cell proliferation effects in cell lines lacking wild-type p53 protein (up to a >3800x on-target index). This latter improvement contrasted with clinical Mdm2 antagonistic molecules. Application of these design rules to a distinct Mdm2(X) peptide series resulted in rapid improvement in cellular activity (>150x) and removal of off-target toxicities. Overall, the detailed workflow outlined here should help researchers identify stapled -helical peptides for therapeutic impact.

biochemistry↗

Stitched peptides as potential cell permeable inhibitors of oncogenic DAXX protein

The death domain associated protein 6 (DAXX) is frequently upregulated in a number of common cancers where its suppression has been linked to reduced tumour progression. As a master regulator protein, with >70 reported protein interaction partners, the role of DAXX in its oncogenecity remains unclear. We designed and developed a set of novel stapled/stitched peptides that target a surface on the N-terminal helical bundle domain of DAXX which is the anchor-point for binding to multiple interaction partners (including Rassf1C, P53, Mdm2 and ATRX) and also for the auto regulation of the DAXX N-terminal SUMO interaction motif (SIM). We demonstrate that these peptides bind to and inhibit DAXX with an affinity higher than those reported for the known interaction partners and release the auto-inhibited SIM for interaction with SUMO-1. NanoBret assays show that the peptides enter cells and that their intracellular concentrations remain at nanomolar levels even after 24 hours, without causing membrane perturbation. Together our data suggest that these peptides are both tools for probing the molecular interactions of DAXX and potential precursors to the development of therapeutics.

biochemistry↗

Derivation of a minimal functional XIST by combining human and mouse interaction domains

XIST is a 17-19 kb long non-coding RNA critical for X-chromosome inactivation. Tandem repeats within the RNA serve as functional domains involved in the cis-limited recruitment of heterochromatic changes and silencing. To explore the sufficiency of these domains while generating a functional miniXIST for targeted silencing approaches, we tested inducible constructs integrated into 8p in a male cell line. Previous results suggested silencing could be accomplished with a transgene comprised of the repeat A which is highly conserved and critical for silencing; the repeat F which overlaps regulatory elements and the repeat E region which contributes to XIST localization by binding proteins such as CIZ1. As PRC1 is recruited through HNRNPK binding of repeats B - C - D we included a second miniXIST comprising AFE with the mouse PID, a 600-nucleotide region of repeat B and C. Silencing of nearby genes was possible with and without PID, however, silencing more distally required the addition of PID. The recruitment of heterochromatic marks, evaluated by IF combined with RNA FISH, revealed that the AFE domains were sufficient only for the recruitment of CIZ1. However, miniXIST transgene recruited all marks, albeit not to full XIST levels. The ability of the PID domain to facilitate silencing and heterochromatic marks recruitment was unexpected, and inhibition of PRC1 suggested that many of these are PRC1-independent. These results suggest that the addition of this small region allowed the partial recruitment of all the changes induced by a full XIST, demonstrating the feasibility of finding a minimal functional XIST.

genetics↗

A Universal Language for Finding Mass Spectrometry Data Patterns

Even though raw mass spectrometry data is information rich, the vast majority of the data is underutilized. The ability to interrogate these rich datasets is handicapped by the limited capability and flexibility of existing software. We introduce the Mass Spec Query Language (MassQL) that addresses these issues by enabling an expressive set of mass spectrometry patterns to be queried directly from raw data. MassQL is an open-source mass spectrometry query language for flexible and mass spectrometer manufacturer-independent mining of MS data. We envision the flexibility, scalability, and ease of use of MassQL will empower the mass spectrometry community to take fuller advantage of their mass spectrometry data and accelerate discoveries.

bioinformatics↗

ztf-16 is a novel heterochronic modulator that opposes adult cell fate in dauer and continuous life histories in Caenorhabditis elegans

Animal development is a complex yet robust process that can withstand lengthy and variable interruptions. In Caenorhabditis elegans, adverse conditions can trigger entry into dauer diapause, a stress-resistant, developmentally arrested stage that occurs midway through larval development. Favorable conditions promote recovery from dauer and the completion of development. During larval development, hypodermal seam cells are multipotent and divide at each stage. At adulthood, seam cells differentiate and express the adult-specific COL-19 collagen. The larval-to-adult transition is controlled by a network of genes called the heterochronic pathway, including the LIN-29 transcription factor that directly activates col-19 expression, and the let-7 microRNA that indirectly promotes lin-29 expression. Notably, most heterochronic genes that oppose adult cell fate are dispensable after dauer. We performed a genetic screen for heterochronic genes that act after dauer and identified ztf-16, encoding a zinc finger transcription factor in the hunchback/Ikaros-like family. We found that ztf-16 opposes precocious expression of the adult cell fate marker col-19p::gfp equally during both life histories, making ztf-16(-) the first precocious heterochronic mutant to be unaffected by dauer. Our data indicate that ztf-16 regulates col-19p::gfp via a novel, lin-29-independent mechanism. Endogenous ztf-16b::gfp expression is regulated by let-7 and ztf-16 acts genetically downstream of let-7, but lin-29 is not required for col-19p::gfp expression in ztf-16 mutant larvae or adults. Taken together, this work illuminates a novel aspect of the heterochronic pathway relevant to both dauer and non-dauer development.

genetics↗

Development of a Novel Peptide Aptamer that Interacts with the eIF4E Capped-mRNA Binding Site using Peptide Epitope Linker Evolution (PELE).

Identifying new binding sites and poses that modify biological function are an important step towards drug discovery. We have identified a novel disulphide constrained peptide that interacts with the cap-binding site of eIF4E, an attractive therapeutic target that is commonly overexpressed in many cancers and plays a significant role in initiating a cancer specific protein synthesis program though binding the 5cap (7methyl-guanoisine) moiety found on mammalian mRNAs. The use of disulphide constrained peptides to explore intracellular biological targets is limited by their lack of cell permeability and the instability of the disulphide bond in the reducing environment of the cell, loss of which results in abrogation of binding. To overcome these challenges, the cap-binding site interaction motif was placed in a hypervariable loop on an VH domain, and then selections performed to select a molecule that could recapitulate the interaction of the peptide with the target of interest in a process termed Peptide Epitope Linker Evolution (PELE). A novel VH domain was identified that interacted with the eIF4E cap binding site with a nanomolar affinity and that could be intracellularly expressed in mammalian cells. Additionally, it was demonstrated to specifically modulate eIF4E function by decreasing cap-dependent translation and cyclin D1 expression, common effects of eIF4F complex disruption.

biochemistry↗

Discovery of cell active macrocyclic peptides with on-target inhibition of KRAS signaling

RAS is the most commonly mutated oncogene in human cancers and RAS-driven tumors are amongst the most difficult to treat. Historically, discovery of therapeutics targeting this protein has proven challenging due to a lack of deep hydrophobic pockets to which a small molecule might bind. The single such pocket available is normally occupied by GDP or GTP which have millimolar cellular concentrations and picomolar affinities for KRAS and hence is challenging to target. The recent FDA approval of sotorasib, a covalent modifier of the KRASG12C mutant protein, has clinically validated KRAS as an oncology target. However, traditional challenges remain for targeting the more common KRAS mutations such as G12D and G12V. As an alternative approach, we investigated the superior binding capacity of macrocyclic peptides to identify KRAS inhibitory molecules. We focused on the recently reported disulfide-cyclized arginine-rich peptide KRpep-2d, discovered through phage display and previously independently confirmed by us as a bona fide KRAS binder. To mitigate intracellular disulfide reduction and loss of binding, we identified an alternate cyclization motif by inverting the configuration of Cys5 and linking it to Cys15 through a thioacetal bridge. The corresponding peptide bound KRAS through cis isomerization of the peptide bond between D-Cys5 and Pro6 as observed through x-ray crystallography. Prototypic molecules displayed measurable cellular inhibition of RAS signaling without membrane lysis and counter-screen off-target activity. An analogue containing azido-lysine confirmed the cell penetrant nature of this molecule using our recently reported NanoClick assay. To improve cellular activity, we sought to improve proteolytic stability. Structure-activity relationship studies identified key scaffold residues critical for binding and revealed that replacement of N- and C-terminal arginine residues with D-arginines and introduction of an -methyl moiety at Ser10 resulted in a molecule with improved proteolytic stability as indicated by its persistence in whole cell homogenate. The resulting peptide MP-3995 had improved and sustained cell-based efficacy. On-target activity was validated through confirmation of target engagement, lack of signaling in irrelevant pathways, and use of non-binding control peptides. Mechanism of action studies suggested that peptide binding to both GDP- and GTP-states of KRAS may contribute to cellular activity. Although validated as bona fide and on-target inhibitors of cell based KRAS signaling, this series is unlikely to advance to the clinic in its current form due to its arginine-dependent cell entry mechanism. Indeed, we showed a strong correlation between net positive charge and histamine release in an ex vivo assay making this series challenging to study in vivo. Nonetheless, these molecules provide valuable templates for further medicinal chemistry efforts aimed at leveraging this unique inhibitory binding site on KRAS. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=118 SRC="FIGDIR/small/459913v1_ufig1.gif" ALT="Figure 1"> View larger version (36K): org.highwire.dtl.DTLVardef@17f4764org.highwire.dtl.DTLVardef@12818daorg.highwire.dtl.DTLVardef@177bdf0org.highwire.dtl.DTLVardef@57046c_HPS_FORMAT_FIGEXP M_FIG C_FIG

biochemistry↗

Detecting change in interconnected ecosystem assets to inform indicators of condition in environmental economic accounts

There is an increasing need for long-term monitoring of ecosystems and their services to inform on-ground management and policy direction. The supply of many ecosystem services relies on connections that span multiple ecosystems. Monitoring the underlying condition of interconnected ecosystems, using established indicators, is therefore required to track effectiveness of past interventions and, ideally, identify impending change. Here we conduct performance testing of ecological indicators for a catchment-to-coast system with the aim of identifying the time-scales over which they respond to change. We chose a case-study of a coastal fishery in Northern Australia that exhibits strong catchment-to-coast connectivity, has long-term available data and is under threat from water resource development. We developed a novel approach to performance testing. Our model drew on state-space modelling to capture ecological dynamics, and structural equation modelling to capture covariation in indictors timeseries. We first quantified covariation among three established ecological indicators: pasture biomass, vegetation greenness and barramundi catch per unit effort. Covariation in the indicators was driven by river flow, with higher values of all indicators occurring in years with greater river flow. We then defined reference bounds for each indicator that accounted for natural variation in river flow. We predicted the emergence times for each indicator, as the time taken for each indicator to emerge from the background of natural variation. Emergence times quantified at 80% and higher confidence levels were >10 years in all cases. Past trends and current status of ecosystem service flows are often used by decision makers to directly inform near-term actions, particularly provisioning services (such as barramundi catch) due to their important contribution to regional economies. We found that the ecological indicators should be used to assess historical performance over decadal timespans, but not as short-term indicators of recent change. More generally, we offer an approach to performance testing of indicators. This approach could be useful for quantifying time-scales of ecosystem response in other systems where cross-ecosystem connections are important.

ecology↗

A novel imaging ligand as a biomarker for mutant huntingtin-lowering in Huntington's disease

Huntingtons disease (HD) is a dominantly inherited neurodegenerative disorder caused by a CAG trinucleotide expansion in the huntingtin (HTT) gene that encodes the pathologic mutant HTT (mHTT) protein with an expanded polyglutamine (PolyQ) tract. While several therapeutic programs targeting mHTT expression have advanced to clinical evaluation, no method is currently available to visualize mHTT levels in the living brain. Here we demonstrate the development of a positron emission tomography (PET) imaging radioligand with high affinity and selectivity for mHTT aggregates. This small molecule radiolabeled with 11C ([11C]CHDI-180R) enables non-invasive monitoring of mHTT pathology in the brain and can track region-and time-dependent suppression of mHTT in response to therapeutic interventions targeting mHTT expression. We further show that therapeutic agents that lower mHTT in the striatum have a functional restorative effect that can be measured by preservation of striatal imaging markers, enabling a translational path to assess the functional effect of mHTT lowering.

neuroscience↗

A cross-cohort analysis of autosomal DNA methylation sex differences in the term placenta

BackgroundHuman placental DNA methylation (DNAme) data is a valuable resource for studying sex differences during gestation, as DNAme profiles after delivery reflect the cumulative effects of gene expression patterns and exposures across gestation. Here, we present an analysis of sex differences in autosomal patterns of DNAme in the uncomplicated term placenta (n=343) using the Illumina 450K array. ResultsUsing a false discovery rate < 0.05 and a mean sex difference in DNAme beta value of > 0.10, we identified 162 autosomal CpG sites that were differentially methylated by sex, and that replicated in an independent cohort of samples (n=293). Several of these differentially methylated CpG sites were part of larger correlated regions of differential DNAme, and many also exhibited sex-specific DNAme variability. Although global DNAme levels did not differ by sex, the majority of significantly differentially methylated CpGs were more highly methylated in male placentae, the opposite of what is seen in differential methylation analyses of somatic tissues. Interestingly, patterns of autosomal DNAme at these significantly differentially methylated CpGs organized placental samples along a continuum, rather than into discrete male and female clusters, and sample position along the continuum was significantly associated with maternal age and newborn birthweight standard deviation. ConclusionsOur results provide a comprehensive analysis of sex differences in autosomal DNAme in the term human placenta. We report a list of high-confidence autosomal sex-associated differentially methylated CpGs, and identify several key features of these loci that suggest their relevance to sex differences observed in normative and complicated pregnancies.

genomics↗